Die-casting machine



Jan. 27, 1959 F. MOSER 2,870,483

DIE-CASTING MACHINE Filed Sept. 24. 1954 s Sheets-Sheet 1 a a INVENTOR- FFY/EDP/(H Mose/Q Bag- 23W,

M46! Q Mm Jan. 27, 1959 F. MOSER 2,870,483

DIE-CASTING MACHINE I INVENTOR. L.. i FRIEDRICH H S R Jan. 27, 1959 V F. MOSER 2,870,483

DIE-CASTING MACHINE Filed Sept. 24, 1954 3 Sheets-Sheet 3 Fig.3

IN VE N TOR l k/EDF/Cfl /10 $52 United States Patent OfiFice 2,870,483 Patented Jan. 2-7, 1959 DIE-CASTING .MACHINE Friedrich Moser, Mendrisio, Switzerland, assignor to 'Ri-Ri Werke A. G., Mendrisio, Switzerland Application September 24, 1954, Serial No. 458,221

Claims priority, application Switzerland September 26, 1953 1 Claim. (Cl. 18--30) The present invention relates to a die casting machine having a hydraulically operated device for opening and closing a vertically closing die and a hydraulically operated device for forcing, the molten material into the die.

Such a die-casting machine may be used for die-casting plastic materials or zinc alloys and more particularly 'for the manufacture of sliding clasp fasteners of the type in which the interlocking members are produced by diecasting directly on the stringers.

According to the invention a longitudinally movable gate distributing piece is connected to the nozzle means in the axial prolongation thereof, said distributing piece comprising a plurality of distributing channels and a casting channel opening into said distributing channels.

Preferably the upper vertically extending die supporting plate is swingably arranged on an axle so that the plate may be swung upwardly together with the die-parts secured thereto. By this arrangement exchanging of damaged parts of the die is facilitated as it is no more necessary to disjoin the whole die-block for this purpose. Moreover cleaning of the die parts is rendered more easy and the arrangement provides easy inspection of the die owing to the good accessability. This accessa'b'ility permits also an easy laying of the stringers when sliding clasp fasteners of the afore-mentioned type are to be produced.

It is a further object of the invention to provide a machine in which the liquefying cylinder for the thermoplastic material as well as the forcing plunger may easily be removed from the top thereof. This is especially advantageous when a repeated exchanging of the liquefying cylinder is necessary as it occurs when a repeated changing of the color of the casting material has to take place.

Other features and advantages of the invention will become apparent from the description now to follow, of a preferred embodiment thereof, and in which reference will be had to the accompanying drawings, in which:

Fig. l is a partly sectional view of the complete diecasting machine for the manufacture of sliding clasp fasteners, comprising a device for opening and closing the die and a device for forcing the melted material into the die.

Fig. 2 is a top view of the die-casting machine of Fig. l with the hydraulically operated pistons of the material supply device as well as the plunger serving to actuate the gate distributing piece, partially shown in section.

Fig. 3 is a side view of the die-casting machine with the hydraulically operated pressure-plungers of the vertically arranged closing plates of the die shown in section.

Fig. 4 is a front view showing the nozzle device and the pouring gate.

Fig. 1 illustrates the die-casting machine with the die closed immediately before the material is forced into the die. Reference numeral 1 designates the plate serving to close the die. This plate 1 is moved to close the die by a centrally arranged piston 2 and, subsequent to the die being closed it is hydraulically locked by the pressure-pistons 3 acting upon the plate. Guiding blocks 4 serve to precisely guide the movement of the closing plate :1. The die-supporting plate 5 is arranged above the closing plate 1 and adjustably connected with the end plate 7 by means of bolt screws 6. The end plate 7 is swingably arranged on an axle -8 so that it may be swung upwardly subsequent to screws 9 having been unscrewed. The material supply device comprises a forcing piston 11 movable in a cylinder 10 and acting upon .a plunger 12 arranged in the boring 13 of the cylinder 14, The forward end of the cylinder 14 carries the nozzle 15. Reference numeral 16 designates the filling apparatus arranged above the cylinder boring 13 and comprising the dosing device 17. The material to be die.- casted falls through a space 18 into the cylinder 14 to which is connected ,a liquefying cylinder 19 which, for exchanging purposes, .is so arranged that it may easily be removed from the top of the machine.

The pressurecylinders .21, serving to displace the nozzle device, are arranged on guiding rods 20 on both sides of and parallel with respect to the forcing piston 11,. In the axial longitudinal prolongation of the pressure cylinders 21 there are provided the plungers 22 serving to actuate the ,gate distributing device 23. Two abut merits 24 are .adjustably arranged on the guiding rods 20 for limiting the stroke .of the nozzle device.

The half 25 of the die is secured to the closing plate 1, while the other half of the die, designated by reference numeral 26 is secured to the supporting plate 5. The two parts of the die, which are shown in closed position in Fig. 1, exactly fit together with their surfaces facing each other. Within the die there are provided the usual grooves serving to receive the stringers, with their thickened edge, of a sliding clasp fastener. Regularly spaced recesses are provided along the grooves for .the stringers, which recesses constitute, when the die is closed and springers arranged in the grooves, the individual moulds for the interlocking members which are to be produced on the stringers by the die-casting process. These individual moulds for the interlocking members are connected with the gate channels of the die which in turn correspond with the distributing channels of the gate distributing device 23.

The described die-casting machine for manufacturing sliding clasp fasteners operates as follows:

A pressure reservoir supplied by pump means maintains the necessary operating pressure. For closing of the die 25, 26 the centrally arranged piston 2 is actuated by the liquid pressure and forces upwardly the closing plate 1. This closing movement results in the four large pistons 3 sucking-in pressure liquid from the reservoir 28 through a conical valve 27. Shortly before the die is entirely closed a high-pressure pump compresses the sucked-in pressure liquid to the adjusted pressure. During the whole die-casting process this high-pressure pump acts directly onto the pistons 3 so that the die is maintained closed under a constant pressure. This closing pressure may be adjusted by a regulating valve provided for this purpose. The casting material cannot be forced into the die before the predetermined closing pressure is attained.

As soon as this closing pressure is attained the gate distributing device 23 is moved forwardly under the action of the two hydraulic pistons 22 and pressed against the front surface of the die. The nozzle system is also moved forwardly and the nozzle 15 is pressed against the gate 30 of the gate distributing piece 23. Hereafter the plunger 12 is knocked forwardly by the forcing piston 11 and forces the dosed volume of material into the liquefying cylinder 19 whereby the already plastified mass contained therein is forced into the dies 25, 26. The

3 forward stroke of the plunger 12 opens the slide 31 of the dosing device 17 and the pro-adjusted amount of casting material is taken from the charging hopper 16. The dosing slide 31 is again closed by the return stroke of the plunger 12 and the dosed mass enters the cylinder 14 through the opening 18.

Subsequent to the return movement of the plunger 12 as Well the nozzle system as also the gate distributing device 22 are hydraulically moved back into their starting position.

Simultaneously with the piston 2 being controlled to effect its return movement the feed conduit from the high-pressure pump to the four locking pistons 3 is adjusted to open into the pressure liquid reservoir resulting in the four pistons 3 being pressure-relieved and the pressure liquid acting upon them being pressed back into the reservoir.

The closing plate 1 now moves downwardly and the spring-loaded supporting plate 5 follows this movement until it abuts against the bolts 6. During this forced downward movement of the supporting plate 5 the dead heads are cut away by cutting blades provided on the end plate 7 and drop into a container 32. As the casting process is finished the casting pieces are pulled rear- Wardly out of the die and new stringers may be pulled from rolls into the grooves of the die. In order to facilitate the laying of the stringers into the grooves of the die a slide may be provided which is adapted to slide over the lower closing or supporting plate and over the die thereby arranging the stringers and laying them into the grooves of the die. This slide may be adapted to be sunk at the end of its to and fro movement.

I claim:

A die casting machine for simultaneously producing a plurality of slide fastener stringers by casting the interlocking elements in rows on a plurality of parallel stringer tapes, comprising a vertically closing two-part die having a horizontal parting face, with grooves for receiving the stringer tapes, with rows of recesses for casting on said tapes the rows of interlocking elements, and with horizontally extending straight gates for supplying the casting material to such recesses, the two parts of said die being formed to present, when the die is closed, a vertical face transverse to and intersected by said parting face, on which vertical face the ends of said gates open; a member for distributing the molten casting material to said gates, which member is horizontally movable toward and away from said vertical face in a direction normal thereto into and out of contact therewith and on its side which contacts said vertical face is formed with a single horizontally extending groove laterally closed by such contact and when so closed forms a channel for supplying and distributing the casting material to said gates, said channel so formed being laterally opened when said member is horizontally moved out of such contact, said member being further formed with a horizontally extending straight through opening normal to and communicating with said groove therein, a nozzle in axial alignment with said through opening mounted for horizontal axial movement into and out of contact with the side of said member opposite said groove therein for supplying molten casting material to said through opening; said gates, groove in said member, through opening, and axial line of said nozzle all lying in the horizontal plane of the parting face of the die; and hydraulically operated means for so moving said member and nozzle and for forcing molten casting material through said nozzle into said through opening when said nozzle is in contact with said member and the latter is in contact with said vertical face, and for holding said nozzle and member in such contact while such material is being so forced.

References Cited in the file of this patent UNITED STATES PATENTS 133,229 Hyatt et a1. Nov. 19, 1872 2,182,884 Stillman et al. Dec. 12, 1939 2,191,882 Ernst et a1. Feb. 27, 1940 2,316,298 Strunk Apr. 13, 1943 2,440,960 Kuzmick May 4, 1948 2,497,951 Low Feb. 21, 1950 2,530,289 Cook Nov. 14, 1950 2,561,021 Groth July 17, 1951 

